Atheism

Oh we're highly likely to see non-Christian faiths and organizations directly criminalized, which will not only be used to prosecute them, but perceived enemies of state that can be accused of being Islam / Hindu / Atheist / Satanist, whatever. But when it comes to Christian denominations, they'll be more inclined first to nudge by erecting policy that enforces specific issues. Then later on, if a given group remains to deviant, they'll be declared not really Christians much the way LDS, Seventh Day Adventists and Jehovah's Witnesses were regarded throughout much of the 20th century. (Curiously, Catholicism is also an issue, what with even Biden fielding challenges to his loyalty to the nation, and not the Holy See.)

Voting blue is the least any one of us can do, and is a necessity just to slow the advancement of the Christian nationalist takeover. The Republican party and the Heretage Foundation are actively and openly working to neuter the democratic elements of the US and to secure Republican domination, which means they don't even have to compete with Democrats, or justify their policy to their followers anymore. They're looking to make us a one-party state.

What we have to do is look into informing independents why they should be voting blue, as well as otherwise disenfranchised groups who still act under the notion we vote for policy rather than against it. (Election reform changing away from FPTP structures is on our wishlist, but unlikely since it diffuses power, and officials are motivated to consolidate power. Until we make such a change, we'll be stuck in a two party system voting against the greater evil by voting for the next most popular guy.)

As for resistance movements, they occur quite naturally, if the history of La Résistance informs. In Paris, the German garrisons couldn't help themselves but be abusive (despite efforts by the Militärverwaltung in Frankreich to discourage brutality) and actually drove independent mischief makers to organizing. It started with tearing down propaganda, cutting phone lines and slashing tires, but it was only a matter of a couple of years before the La Résistance became a formidable organized intelligence and fighting force.

The question is not whether a resistance will form, but if it will be organized before the collapse of democracy or will have to rise up naturally. Since we see what is happening, counter-movements already exists whether anti-fascist groups looking to counter militants whenever they appear to Evangelical Christian sociologist groups (not to be confused with socialist groups) looking to salvage Evangelical Christianity from the anti-communist, pro-capitalist, nationalist monstrosity that is preached in dozens of ministries today.

Germany had its own resistance movements like The White Rose, most of which went underground or were captured and executed as the German Reich took power, though the July 20 plot (and thirty-odd other attempts to assassinate Hitler) show us that resistance within Germany existed late into the war, and likely lingered underground to the bitter end.